Infective endocarditis is an infection inside the chambers of the heart or on the heart valves. Infectious endocarditis may be triggered by a clot forming on the lining of the heart or on one of its valves in response to damage on the valve surface. Once this clot forms, bacteria that may be present in the bloodstream (bacteremia) can stick to the clot and proliferate (multiply) within it, eventually interfering with the heart's function.
Bacteremia is a normal occasional result of daily activities such as brushing your teeth or other activities such as medical and dental procedures. The surfaces of the mouth, urinary tract, and gastrointestinal tract have many different kinds of bacteria growing on them. Any procedure that breaks down this surface can temporarily shower the bloodstream with bacteria, which are usually killed by the body's immune system.
In normal hearts, temporary bacteremia usually has no consequences. However, if there are clots or injury to the heart lining and valves or the person has a prosthetic valve (made of synthetic material), an immune response to kill bacteria in the clot might not be triggered, and infective endocarditis can
Lifelong antibiotics are not necessary to prevent infective endocarditis. Prophylactic (preventive) antibiotics should be given to people who are most likely to have severe complications if they develop infective endocarditis. In such people, prophylactic antibiotics are recommended before dental procedures, which have the highest risk of causing bacteria to enter the blood. There is no evidence to recommend using antibiotics before procedures on the gastrointestinal or urinary tracts.
Antibiotic prophylaxis should be considered in people with
Prosthetic heart valves
Past episodes of infective endocarditis
Heart transplants who develop disease in their heart valves
Congenital (present since birth) heart diseases who have had prosthetic materials or devices placed in their heart within the last 6 months
Congenital heart diseases whose heart defects have not been completely fixed or have remaining defects at or near where a prosthetic patch or device was placed
For patients who require prophylactic antibiotics, these medications ideally should be given before a dental procedure. If this dose is missed, patients can receive antibiotics up to 2 hours after the procedure.
The most commonly prescribed antibiotic is oral penicillin. People who are allergic to penicillin can be given cephalosporins, macrolides (different classes of antibiotics), or clindamycin. There are injectable forms of these antibiotics for people who cannot take medication by mouth.
American Dental Association www.ada.org/2157.aspx
National Heart, Lung, and Blood Institute www.nhlbi.nih.gov/health /health-topics/topics/endo /prevention.html
American Heart Association
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Sources: American Heart Association, Mayo Clinic
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Topic: HEART HEALTH
Punnoose AR, Lynm C, Golub RM. Antibiotics to Prevent Infective Endocarditis. JAMA. 2012;308(9):935. doi:10.1001/jama.2012.6918