What is Endocarditis?

Endocarditis is an infection of the inner lining of your heart chambers and valves (called the Endocardium). This infection is caused when bacteria, fungi, or germs from your body (such as your mouth), enter the bloodstream and attach to the heart. Left untreated, the infection causes inflammation that can severely damage your heart. This can be life-threatening.

Endocarditis is also known as bacterial endocarditis or infective endocarditis. Endocarditis that is not caused by infection is called non-infective endocarditis.

Infective Endocarditis

Infective endocarditis has several unique characteristics and subcategories:

  • Infective endocarditis (or bacterial endocarditis) is classified into two sub-categories: acute infective endocarditis and subacute infective endocarditis.
    • Acute infective endocarditis: This form of endocarditis develops rapidly and can become life threatening quickly, often within a matter of days. Acute infective endocarditis is also occasionally referred to as acute endocarditis.
    • Prosthetic valve endocarditis: This is a type of acute endocarditis that occurs in prosthetic heart valves.
  • Subacute infective endocarditis: This type of endocarditis is also known as subacute bacterial endocarditis. It develops over the course of several weeks or months with symptoms slower to present and sometimes not showing until the later stages of development. Although this type of infective endocarditis is not as rapid as acute infective endocarditis, it can still be life-threatening.

Non-Infective Endocarditis

Non-infective endocarditis has the following properties:

  • Non-infective endocarditis is also referred to as nonbacterial thrombotic endocarditis (NBTE).
  • Non-infective endocarditis is not caused by bacteria, fungus or germs.
  • Non-infective endocarditis occurs when blood clots (sterile platelet and fibrin thrombi) form on heart valves and nearby endocardium.
  • Non-infective endocarditis can lead to infective endocarditis.


Endocarditis occurs when germs enter the bloodstream and reach the heart, multiplying and attaching to atypical heart valves or damaged heart tissue. Overgrown bacteria are the most common cause of endocarditis, although fungi and other microorganisms can sometimes be responsible for the condition. The immune system usually destroys harmful bacteria that makes it into the bloodstream, but sometimes bacteria makes it through the bloodstream and into the heart. Normal heart valves are resistant to infection, but diseased, damaged, or prosthetic heart valves are more prone to bacteria which forms endocarditis.

Bacteria and germs enter the bloodstream in several predictable ways. The following are common endocarditis causes:

  • Injury to the mouth, gums or skin.
  • Regular teeth brushing.
  • Flossing the teeth.
  • Gum disease (also known as Gingivitis).
  • Certain dental procedures (such as tooth extraction that involve cutting the gums).
  • Skin sores, abrasions or openings.
  • Sexually transmitted diseases (STDs).
  • Catheters (usually longer-term use).
  • Certain intestinal disorders (including inflammatory bowel disease).
  • Needles when getting tattoos.
  • Needles when getting body piercings.
  • Illegal intravenous (IV) drug injection (especially with used or unclean needles).

If enough bacteria enter the bloodstream, or if aggressive bacteria enter the bloodstream, endocarditis can develop even on healthy heart valves.

Signs and Symptoms

Endocarditis symptoms vary from person to person. They may also develop rapidly (acute) or more slowly over time (subacute).

Signs of endocarditis:

  • Sweats or chills (especially at night).
  • Feeling tired, weak or fatigued.
  • Reduced appetite or unexplained weight loss.
  • Sore, irritated or itchy throat.
  • Pain, tenderness, or discomfort in your joints or muscles.
  • Pain or discomfort when swallowing.
  • Pain or discomfort on the left side of your body under your ribcage (this may be your spleen fighting an infection).
  • Cough (either dry or moist) that lasts more than 48 hours (2 days).
  • Nausea, vomiting or diarrhea.
  • Blood in your urine.
  • High fever (over 100°F).
  • Sinus drainage or nasal congestion.
  • Headaches or tenderness in the cheekbones (especially the upper region).
  • Appearance of white patches in your mouth or on your tongue.
  • Skin rash or redness.
  • Swelling in your feet, legs or abdomen.
  • Clubbed fingernails or toenails (Nails curved around enlarged tips of fingers or toes).
  • Redness in the whites of your eyes.
  • Scrape, cut or wound that does not heal.
  • Sores that appear red, warm or that drain fluid.
  • Paleness (whiteness) of limbs.


Your doctor will use a variety of tests to diagnose endocarditis. Tests will also determine the type of endocarditis (infective or non-infective). Based on the results of the tests, your doctor will proceed with tailored treatments.

Diagnosing endocarditis can involve the following tests:

  • Echocardiogram: This is the primary test used for diagnosing endocarditis. The echocardiogram test uses sound waves to produce images of your heart. It can be used to check for signs of infection. Your doctor may use one of two types of this test: a transthoracic echocardiogram or a transesophageal echocardiogram.
  • Blood tests: Blood tests help identify bacteria or fungi in your bloodstream. This is the most important test a doctor will perform because treatment for infective endocarditis differs from treatment for non-infective endocarditis.
  • Electrocardiogram (ECG): While an ECG is not used specifically to diagnose endocarditis, it can show your doctor if your heart’s electrical activity is affected. An endocarditis ECG looks different than an ECG of a patient without the condition.
  • Chest X-Ray: X-Ray images can help your doctor identify an enlarged heart (sometimes caused by endocarditis) or if any infection has spread to your lungs.
  • Computerized tomography (CT) scan or magnetic resonance imaging (MRI): Your doctor may conduct imaging tests to determine if the infection has spread to your brain, chest, or other parts of your body.


Endocarditis treatment is customized to each person based on risk factors, symptoms, severity of the condition, results of diagnostic tests and type of endocarditis (infective or non-infective). The two primary treatments are medication and surgery.

Most cases of endocarditis can be resolved with a regime of antibiotics taken over the course of two to six weeks. You can expect to temporarily stay in the hospital so that medication can be administered intravenously through an IV line inserted into your arm, and so that regular blood tests can be taken to track the effectiveness of the treatment. For severe endocarditis, a mixture of antibiotics may be prescribed before the results of the blood tests arrive, as a preventive measure. Once you are no longer experiencing symptoms, you may be able to leave the hospital. In this case, your doctor will generally prescribe antibiotics for you to take at home, and likely also schedule regular follow-up appointments to track the progress of the infective endocarditis treatment. Antifungal medication may be prescribed if your endocarditis is determined to be caused by fungus.

Surgery can help repair a heart damaged by endocarditis. Surgery may be recommended for the following reasons:

  • If you have experienced heart failure (or if your symptoms or results of diagnostic tests indicate possible heart failure).
  • If you experience ongoing high temperature (fever) even with antibiotic or antifungal treatment.
  • If persistent (aggressive) fungi or drug-resistant bacteria is responsible for your endocarditis.
  • If you develop 1 (or more) blood clots even with antibiotic or antifungal treatment.
  • If you have a prosthetic heart valve (they are more vulnerable to infection).
  • If abscesses or fistulas have developed inside your heart (based on ECG results).

The primary surgical procedures you might receive:

  • Surgery to fix damaged heart valves.
  • Surgery to restore the damaged heart valves with prosthetic replacements.
  • Surgery to drain abscesses and to repair fistulas (abnormal passages) that endocarditis may have caused in the heart muscle.

Risk Factors

There are several risk factors for developing endocarditis. Even if you have a healthy heart, it is still possible to develop infective endocarditis or non-infective endocarditis.

Risk factors include the following:

  • Injecting intravenous drugs with a contaminated needle.
  • Scarring from heart valve damage (This allows bacteria and germs to reproduce).
  • Tissue damage caused by past endocarditis.
  • Previous history of heart defects.
  • Previously undergoing an artificial heart valve replacement.

Next Steps with MyChart

Discover MyChart, a free patient portal that combines your Baptist Health medical records into one location. Schedule appointments, review lab results, financials, and more! If you have questions, give us a call.