Endocarditis: What You Need to Know

Endocarditis is an infection of the endocardium, which is the inner lining of the heart. Although uncommon, it is a serious condition and typically requires hospitalization to receive intravenous (IV) antibiotics. Full treatment and recovery could take 6 weeks or longer. Endocarditis is not common, affecting 3–10 people for every 100,000. Also called infective endocarditis (IE), this condition often results from bacteria that have traveled to the heart from other parts of the body.

Without treatment, the infection could spread beyond the heart, potentially leading to stroke or death.

Read on to learn more about the types, causes, symptoms, and treatments for endocarditis.

According to the American Heart Association (AHA), there are two main types of endocarditis.

Acute infective endocarditis develops rapidly and can progress quickly to become life threatening.

Subacute IE, also called chronic IE, may take weeks or months to develop.

Some experts split endocarditis into a third type called prosthetic valvular endocarditis (PVE). PVE is a rare condition that occurs in 2–3% of people who have had surgery to implant a prosthetic valve or replace valve tissue.

Endocarditis develops when bacteria from other parts of the body travel to the endocardium, where they attach and grow. If there is damage to the endocardium or heart valves, they become more susceptible to infection.

Masses of cells and bacteria called vegetations form and negatively affect heart function. Vegetations can cause abscesses and leaks in the valves or blockages in veins.

There are various ways for bacteria to enter the bloodstream, where they can reach the inner lining of the heart and heart valves. They include:

• by mouth, such as while eating or brushing your teeth
• infection in other parts of the body
• sexually transmitted diseases
• medical procedures involving syringes, urinary catheters, dialysis tubes, and laparoscopes
• IV drug use

In rare cases, fungi can also cause endocarditis.

Some of the most common symptoms of endocarditis are persistent fever, shortness of breath, and fatigue. Doctors may also hear a new or changed heart murmur.

Other symptoms of endocarditis may include:

• chills
• rapid heart rate
• night sweats
• swelling in the abdomen and lower extremities
• headaches
• cough
• chest pain
• muscle and joint pain
• loss of appetite
• blood in urine
• painless red spots on the palms and soles
• small red or purple spots on the skin
• painful bumps on fingertips and toes
• small red spots in the eyes and under the fingernails

To diagnose endocarditis, doctors typically start by assessing your medical history and performing a physical examination. They may also order additional tests to narrow down the cause and determine the best treatment method.

These tests may include:

• Blood tests: These tests can check for bacteria or fungi and inflammation in your body.
• Transthoracic echocardiogram (TTE): This test involves placing an ultrasound probe on your chest to create detailed images of the heart. Doctors can use it to locate vegetations or check for damaged heart tissue. TTE is typically a preferred diagnostic step prior to a transesophageal echocardiogram, which is more invasive and requires sedation.
• Transesophageal echocardiogram (TEE): This test, which involves inserting a scope down through your esophagus, can create clearer pictures of the heart than TTE.
• CT scan: This scan allows doctors to check for abscesses in the heart.

Treatment for endocarditis typically requires a course of antibiotics lasting 4–6 weeks. You may need to spend the first 2 weeks in the hospital to receive the antibiotics intravenously. In some cases, the whole course may require hospitalization.

If the affected heart valve interferes with heart function, surgery may be necessary to repair or replace it. Doctors may also perform surgery to drain any abscesses or repair any ruptures in the heart.

If the infection is fungal instead of bacterial, treatment can include antifungal medicines combined with surgery.

The outlook for people with endocarditis improves with early diagnosis and treatment. Failure to receive prompt treatment can lead to severe heart damage.

Within the first 30 days of infection, experts estimate that the mortality rate is approximately 20%. Without treatment, the condition typically results in death.

Potential complications of endocarditis include:

• congestive heart failure
• arrhythmias, or irregular heartbeats
• stroke
• brain hemorrhage
• abscesses in the heart, lungs, brain, or other areas of the body
• arterial embolism, or a blockage in the arteries
• aneurysm

Although it is less common, endocarditis can also cause acute kidney failure.

Those at high risk for endocarditis include people with a pacemaker or artificial heart valve, those born with heart defects, and anyone with a weakened immune system. Using recreational drugs by injection also increases risk.

Other risk factors for endocarditis include:

• being male
• being older than 65 years
• having diabetes
• having poor oral hygiene
• having calcium deposits in the mitral or aortic heart valves

In addition, people who have had endocarditis once are more likely to get it again.

To help prevent endocarditis, doctors may recommend that high risk people undergoing dental procedures take antibiotics beforehand.

The following steps may also help prevent endocarditis:

• Maintain good oral hygiene.
• Wash your hands frequently for a minimum of 20 seconds.
• Avoid or take safety precautions for tattoos, body piercings, IV drugs, and other activities that could lead to a skin infection.

These are a few other commonly asked questions about endocarditis. The answers have been medically reviewed by Dr. Megan Soliman.

Researchers estimate that approximately 75% of people with endocarditis survive with treatment. Survival without treatment is unlikely.

It is possible to cure endocarditis with prompt and aggressive treatment. Treatment typically requires a lengthy course of antibiotics, and sometimes surgery is necessary to repair or replace damaged heart tissue.

Endocarditis is a serious infection of the inner lining of the heart. Bacteria are the most common cause of the infection, although in rare cases, fungi may contribute. Symptoms can include fever, fatigue, heart murmur, and shortness of breath.

Treatment usually begins in the hospital and involves receiving IV antibiotics. In some cases, surgery may be necessary to repair or replace damaged heart tissue or valves. People at high risk of contracting endocarditis may need to take antibiotics before dental procedures.

Talk with your doctor right away if you are experiencing symptoms consistent with endocarditis. Prompt treatment is critical to reducing your risk of long term heart damage and other serious complications.