What is bacterial endocarditis?

Bacterial endocarditis, also called infective endocarditis, is an infection caused by bacteria. The bacteria enter the bloodstream and settles in the heart lining, heart valves, or a blood vessel. The heart has 4 valves. These valves help the blood flow through the heart and lungs and out to the body. When a person has bacterial endocarditis, these valves may not work correctly. This can force the heart to work harder to get blood out to the body. Sometimes the heart can’t pump out enough blood. Bacterial endocarditis is a serious condition that can sometimes lead to death, especially if not treated right away.

Bacterial endocarditis can also cause the bacteria to clump with platelets, fibrin, and other substances in the blood. These clumps are often called vegetations. They can travel to many other parts of the body and cause problems.

In adults, bacterial endocarditis is more common in men than in women. Bacterial endocarditis is uncommon, but it is much more common in people with certain heart problems or other risk factors.

In some cases, the symptoms start suddenly and are severe. This is called acute bacterial endocarditis. In other cases, it happens more slowly and is less severe. This is called subacute bacterial endocarditis.

What causes bacterial endocarditis?

Some kinds of bacteria normally live on and in the body. They live in the mouth, in the respiratory system, on the skin, and in the digestive tract. Sometimes these bacteria can get into the bloodstream. This may happen after a medical or dental procedure that breaks the skin or other tissue. Bacteria go into the bloodstream and can settle on the heart lining or on the heart valves.

Not all types of bacteria can cause this kind of infection, but many types can. Two kinds of bacteria cause most cases of bacterial endocarditis. These are staphylococci (staph) and streptococci (strep).

You may be at increased risk for bacterial endocarditis if you have certain heart valve defects. This gives the bacteria an easier place to take hold and grow. It is uncommon for a person with a normal heart to get endocarditis.

Who is at risk for bacterial endocarditis?

Risk factors that may increase the chance of getting bacterial endocarditis include:

• IV (intravenous) drug use

• Hemodialysis for kidney failure

• Heart valve disease, such as leaking or narrowed valve

• Rheumatic heart disease caused by strep bacteria

• Implantable cardiac device

• Heart disease present at birth (congenital)

• Past history of endocarditis

• Poor dental hygiene

• Artificial heart valves or valve repair or replacement

• Heart transplant with a leaky heart valve

• Weak immune system

What are the symptoms of bacterial endocarditis?

Symptoms may come on suddenly and be severe. Or, they may happen slowly and be less severe. Symptoms may include:

• Fever or chills

• Night sweats

• Fatigue

• Aching muscles and joints

• Trouble breathing with activity

• Shortness of breath while lying down

• Cough

• Nausea

• Vomiting

• Headaches

• Blood in the urine

• Swelling of the feet, legs, or abdomen

• Weight loss

• Abnormal skin changes that may include:

  • Sore red or purple bumps on the fingers or toes

  • Painless, tiny flat red spots on the skin, under fingernails, on the whites of your eyes, and inside your mouth

How is bacterial endocarditis diagnosed?

Your healthcare provider will ask about your symptoms and your health history. They will give you a physical exam.

You may also need tests, such as:

• Echocardiogram to view how well the heart is pumping blood and how well the heart valves are working.

• Transesophageal echocardiogram for more detailed view of the heart from the esophagus

• Blood tests and cultures to check for specific bacteria, infection, and signs of inflammation

• Electrocardiography (ECG) to check how well your heart is functioning by measuring the electrical activity of the heart.

• Chest X-ray to examine your lungs

• Cardiac CT scan or MRI scan, if more information is needed about your heart

• Scans of brain, chest, or other parts of your body if your healthcare provider thinks the infection has spread

How is bacterial endocarditis treated?

Antibiotics are the main treatment for bacterial endocarditis. The type of antibiotic depends on several factors. These include the type of bacteria, and if you have an artificial heart valve. A team of healthcare providers will work together to decide the best treatment plan for you. This team will likely include a cardiologist, an infectious disease healthcare specialist, a pharmacist, and a heart surgeon. The surgeon is included if you have a lot of heart damage and may need surgery.

You will need to take antibiotics for many weeks. At first, you’ll be given antibiotics through an IV line. You may need to spend at least the first week of treatment in the hospital. After that, you may be able to have IV antibiotics at home with home-based care. Later in your treatment, you may be able to take oral antibiotics.

Heart surgery may be needed to repair or replace damaged valves, remove vegetations, or drain abscesses if antibiotics do not work, a valve leaks significantly, or a birth defect connects one chamber to another.

What are possible complications of bacterial endocarditis?

Bacterial endocarditis causes clumps of bacteria and cells start to form on the heart valves. These clumps can break free into the bloodstream. They can then cause damage by blocking other blood vessels. They can also spread the infection to other organs. Because of this, there are many possible complications. Many of these are serious. The risk of these complications varies depending on a person’s other medical conditions. Possible complications include:

• Heart failure

• Heart valve damage

• Heart block

• Heart attack

• Brain abscesses

• Meningitis

• Stroke

• Seizures

• Blood clot in the lung (pulmonary embolism)

• Pneumonia

• Kidney infection and damage

• Spleen enlargement and damage

• Failure to cure the infection

• Death

What can I do to prevent bacterial endocarditis?

Not all cases of bacterial endocarditis can be prevented. But you can lower some of these risks. For example, prompt treatment of a strep infection can help prevent rheumatic heart disease. Not using IV drugs can lower your risk. Keeping your mouth clean and healthy can also lower your risk.

You may need to take antibiotics before some medical and dental procedures. This is to help prevent endocarditis if you have an artificial heart valve. Or if you had heart valve repair with artificial material. You may need to take antibiotics if you have certain kinds of congenital heart disease, a history of endocarditis, or had a heart transplant with a leaky heart valve. Tell all of your healthcare providers and dentists about your heart health history.

When should I call my healthcare provider?

See a healthcare provider right away if you have any symptoms of endocarditis.

Key points about bacterial endocarditis

• Bacterial endocarditis is an infection of the heart’s inner lining or heart valves. It's a serious condition that needs to be treated right away.

• Endocarditis can cause serious complications. It can also lead to death.

• See a healthcare provider right away if you have any symptoms of endocarditis.

• Endocarditis is treated with antibiotics. In some cases, surgery may be needed.

• Follow all of your healthcare provider’s instructions. Take your medicines as prescribed. Keep all of your follow-up appointments.

• Make sure to tell all of your healthcare providers and dentists about your heart health history. You may need to take antibiotics before some medical or dental procedures. This is to help prevent endocarditis.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions.