Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at March 29, 2016

An infection of the endocardium, the inner lining of the heart, endocarditis often affects people with heart defects, damaged heart valves or artificial heart valves in their heart. Endocarditis most often begins when bacteria or germs from other parts of the body enter the bloodstream and reach damaged heart tissue. The resulting infection can cause damage to heart valves, even destroying them. Endocarditis can lead to fatal complications.


Definition & Facts

Endocarditis is an infection or inflammation of valves of the heart or of the heart's inner lining. Particularly vulnerable to this infection are people who have a damaged or artificial heart valve, those with heart defect, or who have experienced heart surgery. Heart failure, stroke, and death often result from endocarditis.

Endocarditis begins when bacteria from the mouth or other parts of the body move through the bloodstream and into the heart. Once in the heart, the bacteria grows on one of the valves. This growth becomes a mass called a vegetation. Transesophageal echocardiography (TEE) is the most accurate means of detection of endocarditis vegetation growth in a heart valve.

Symptoms & Complaints

Onset of symptoms of endocarditis may be slow or sudden. These symptoms can also be very non-specific. What symptoms appear and how rapidly they are known depends largely on what is causing the infection and whether the affected individual has pre-existing heart problems. Although symptoms can vary widely from person to person, these signs of endocarditis may include:

If these symptoms are present, it is important to see a doctor. This is particularly true if you have a heart defect, history of heart surgery, mechanical valves in your heart or a prior case of endocarditis. Symptoms are similar whether the case of undiscovered endocarditis is minor or more serious. Seeing a doctor as early as possible is important.


When germs are or bacteria are present in the body, they can travel through the bloodstream to other parts of the body and cause infection to develop in those areas. This is how endocarditis begins. Bacteria, fungi or other microorganisms have traveled to the heart through blood and attached to abnormal heart valves or tissue of the heart which has been previously damaged.

Common bacteria of the mouth and throat can cause endocarditis. Below are some indirect causes of endocarditis, health conditions from which offending bacteria or other germs have entered the blood and reached the heart:

  • Oral activities of everyday life, such as brushing teeth or chewing food, particularly if good oral health is not maintained.
  • Infection or medical conditions in the body, from which bacteria may spread. Frequent conditions leading to endocarditis can be gum disease, sores, sexually transmitted diseases, or intestinal disorders.
  • Use of catheters or needles through which bacteria can enter the body, such as medical needles or even those used for tattoos or body piercing.
  • During dental procedures, particularly if gums are cut and bacteria is able to enter the bloodstream through the wound.

For healthy individuals, bacteria entering the bloodstream does not always cause endocarditis. The body's immune system usually works to eliminate bacteria before infection can start. This means that the blood can carry bacteria directly to the heart in a healthy body without endocarditis resulting.

Endocarditis is more commonly seen in people with damaged or diseased heart valves, where bacteria settle. Damaged tissue provides a roughened surface for bacteria to lodge and multiply. There are occasional cases of endocarditis in people who have healthy hearts without any heart valve damage or dysfunction, however.

Diagnosis & Tests

Physical signs and symptoms, combined with medical history of heart valve damage or other heart problems, may lead a doctor to suspect endocarditis. A new or changed heart murmur can be heard through a stethoscope. Such heart sounds also indicate possible endocarditis.

Endocarditis can appear similar to other illnesses in the condition's beginnings. This makes further testing important for clear diagnosis of the heart infection. Those tests may include:

  • Blood testing, including a blood culture for identification of bacteria in the bloodstream. Anemia and other conditions commonly associated with endocarditis can also be identified through blood testing.
  • Transesophageal echocardiogram, sound wave imaging to visualize the heart as it works and to evaluate heart valve condition.
  • Electrocardiograms, to detect a possible irregular heartbeat by measuring the timing and duration of heartbeat electrical phases.
  • Chest X-rays, to examine condition of heart and lungs and to see if lung infection is present or the heart has enlarged.
  • CT scan or MRIs to evaluate health of the brain, chest or other regions of the body that may also be affected by the blood traveling bacteria.

Treatment & Therapy

There are two primary means of treating endocarditis. Those are antibiotic administration to alleviate infection and surgery, when heart valve damage has been caused by the offending bacteria. High doses of intravenous (IV) antibiotics are the first means of treating endocarditis in the hospital. These antibiotics are selected after blood tests help to identify the type of microorganism infecting the heart. One antibiotic may be delivered through IV or a combination of several may be used, depending upon the type of bacteria responsible.

A course of antibiotics will continue through oral administration for six weeks or more. This will help eliminate the infection entirely. Patients who are permitted to leave the hospital after initial IV antibiotics may be instructed to continue IV antibiotic therapy at home. This will involve home care or visits to the doctor during continued treatment. All patients with endocarditis diagnosis must visit their doctor until the condition has been alleviated.

During treatment, signs and symptoms of infection can worsen. It is important for patients to advise their doctors if this is happening, so treatment may be adjusted. Some of the symptoms include:

Presence of diarrhea, itching, joint pain or rashes during treatment for endocarditis may indicate antibiotic allergy. Shortness of breath or swelling in lower extremities may indicate heart failure. In the case of any of these symptoms during treatment, the doctor should be notified immediately.

When infection damages heart tissue, complications and symptoms of endocarditis can continue for years. Surgery can treat more persistent infections such as infections caused by fungus, and surgery may also replace damaged heart valves. Heart valves can sometimes be repaired during surgery, although many are replaced by animal tissue valves or those constructed of manmade materials.

Prevention & Prophylaxis

It is possible to take measures to prevent endocarditis. Two of these measures are good hygiene and preventive antibiotics. Dental health is particularly important in prevention of endocarditis. Teeth and gums must be brushed and flossed often and dental exams performed regularly.

Any procedures that are known to cause skin infections in some people should be avoided, such as tattooing or piercings. When skin infections do develop, those at risk for endocarditis due to heart condition history should contact their doctor. Prompt medical attention should be sought if skin infections, cuts or sores do not heal well.

For people at risk for endocarditis, precautionary measures should be taken before some dental or medical procedures. These measures include starting antibiotics before the procedures to ensure any harmful bacteria able to enter the bloodstream are eliminated. Procedures as part of which preventive antibiotics should be considered include:

  • Dental procedures that may cut gum tissue or teeth
  • Procedures of the respiratory tract or infected skin or tissue, particularly tissue connecting muscle to bone
  • It is no longer considered appropriate to administer antibiotics before all dental procedures or for those involving the urinary tract or GI system.