Bacterial endocarditis is an inflammation of the inner lining of the heart (endocardium) and particularly the heart valves, due to infection. Infection may also occur at the site of a septal defect (birth defect in which there is a hole between the left and right sides of the heart), on the chordae tendineae (small tendons attached to the heart valves), or in the endocardium itself. Endocarditis may occur alone or as a complication of another disease. The infection can be caused by any number of microorganisms. It is classified as acute or subacute. The incidence of bacterial endocarditis increases with age. Men have a higher incidence than females.
Endocarditis occurs when germs enter your bloodstream, travel to your heart, and attach to abnormal heart valves or damaged heart tissue. Bacteria cause most cases, but fungi or other microorganisms also may be responsible.
Sometimes the culprit is one of many common bacteria that live in your mouth, throat or other parts of your body.
- Everyday oral activities. Activities such as brushing your teeth or chewing food can allow bacteria to enter your bloodstream — especially if your teeth and gums are in poor condition.
- An infection or other medical condition. Bacteria may spread from an infected area, such as a skin sore. Gum disease, a sexually transmitted disease or an intestinal disorder — such as inflammatory bowel disease — also may give bacteria the opportunity to enter your bloodstream.
- Catheters or needles. Bacteria can enter your body through a catheter — a thin tube that doctors sometimes use to inject or remove fluid from the body. The bacteria that can cause endocarditis can also enter your bloodstream through the needles used for tattooing or body piercing.
- Certain dental procedures. Some dental procedures that can cut your gums may allow bacteria to enter your bloodstream.
- Fatigue and weakness
- Intermittent fever, chills and excessive sweating, especially at night
- Weight loss
- Vague aches and pains
- Heart murmur
- Severe chills and high fever
- Shortness of breath on exertion
- Swelling of the feet, legs and abdomen
- Rapid or irregular heartbeat
- A blood test is the primary test for bacterial endocarditis. Three to five blood samples may be taken in a 24-hour period to determine the presence of the bacteria.
- A urine sample also may indicate the presence of infection but is not adequate by itself for the diagnosis.
- An echocardiogram may detect an abnormality, such as a mass on a heart valve or on the heart wall surface, called a vegetation.
Bacterial endocarditis usually can be prevented by taking antibiotics immediately before and after procedures in which bacteria may be released into the bloodstream, such as:
- Dental cleaning
- Gallbladder or prostate surgery
- Some surgeries in the respiratory passageways, or the gastrointestinal or urinary tracts
- Tonsillectomy and adenoidectomy
People at risk for bacterial endocarditis are encouraged to practice good oral hygiene.
Once endocarditis is diagnosed, treatment usually consists of intravenous antibiotics. Recovery may take four to six weeks and there is a risk of permanent heart damage.
Endocarditis can cause several major complications:
- Stroke and organ damage. In endocarditis, clumps of bacteria and cell fragments (vegetations) form in your heart at the site of the infection. These clumps can break loose and travel to your brain, lungs, abdominal organs, kidneys or extremities. This may cause various problems, including stroke or damage to other organs or tissues.
- Infections in other parts of your body. Endocarditis can cause you to develop pockets of collected pus (abscesses) in other parts of your body, including the brain, kidneys, spleen or liver. An abscess may develop in the heart muscle itself as well, causing an abnormal heartbeat. Severe abscesses may require surgery to treat them.
- Heart failure. Left untreated, endocarditis can damage your heart valves and permanently destroy your heart's inner lining. This can cause your heart to work harder to pump blood, eventually causing heart failure — a chronic condition in which your heart is unable to pump enough blood to meet your body's needs. If the infection progresses untreated, it's usually fatal.