Bacterial endocarditis is an infection of the inner lining of the heart and the associated internal heart structures, such as the heart valves. This infection can occur in any person (infant, child or adult) who has heart disease present at birth (congenital heart disease), or can occur in people without heart disease.

Bacterial endocarditis does not occur very often, but when it does, it can cause serious heart damage. It is very important to prevent this infection from occurring, if possible.

Cause of Infection

Bacterial endocarditis occurs when bacteria (germs) enter the bloodstream and lodge inside the heart, where they can multiply and cause infection.

A normal heart has a smooth lining with normal valve structures, making it difficult for bacteria to stick to them. Persons with congenital heart disease may have abnormal inner heart linings due to thickened valves that cause abnormal opening or leaking of the valve. Even after surgery, roughened areas may remain due to scar tissue formation or surgical patches used to redirect blood flow. These rough areas inside the heart are inviting and opportune places for bacteria to build up and multiply.

How Bacteria Enters the Body

Bacteria can enter the body in many ways. According to the American Heart Association (AHA), some of the most common ways include:

• Dental procedures (including professional teeth cleaning)
• Tonsillectomy or adenoidectomy
• Examination of the respiratory passageways with an instrument known as a rigid bronchoscope
• Certain types of surgery on the respiratory passageways

Risk Factors for Bacterial Endocarditis

Any infant, child or adult who has cyanotic congenital heart disease that has not yet been repaired can develop bacterial endocarditis. Some people who have already had a heart defect repaired may also need to take precautions against bacterial endocarditis for the rest of their lives, while others may no longer need to observe these precautions. According to the American Heart Association, heart problems that put children at risk for developing bacterial endocarditis include:

• Prosthetic (artificial) heart valves
• A previous history of endocarditis (even in the absence of other heart disease)
• Complex repaired or unrepaired cyanotic congenital heart disease (due to insufficient oxygen in the blood)
• Surgically constructed systemic pulmonary shunts or conduits with residual defects at the site or adjacent to the site of a prosthetic patch or device. 
• Cardiac transplantation recipients who develop valvulopathy acquired valve dysfunction, such as due to rheumatic heart disease or collagen vascular disease

Consult your child's physician with any further questions you may have about risk factors.

Diagnosis of Bacterial Endocarditis

In addition to a complete medical history and physical examination of your child, diagnostic procedures may include:

• Echocardiogram (echo), a procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves
• Complete blood count (CBC), a measurement of size, number, and maturity of different blood cells in a specific volume of blood
• Blood culture, a test that assesses for and determines the specific type of bacteria in the bloodstream, if any

Prevention of Bacterial Endocarditis

Helping your child maintain excellent oral hygiene is an important step in preventing bacterial endocarditis. Regular visits to the dentist for professional cleaning and check-ups are essential. Proper oral hygiene is crucial, including regular brushing and flossing.

Prior to procedures that put your child at risk, such as those mentioned above, a dose of an antibiotic is given. In most cases, the antibiotics can be given by mouth instead of through a shot or an intravenous (IV) line. Your child's dentist, pediatrician, or cardiologist can provide an antibiotic prescription for you and your child.

Treatment for Bacterial Endocarditis

Specific treatment for bacterial endocarditis will be determined by your child's physician based on:

• Your child's age, overall health, and medical history
• Extent of the infection
• Bacterial cause of the infection
• Your child's tolerance for specific medications, procedures, or therapies
• Expectations for the course of the infection
• Your opinion or preference

Bacterial endocarditis is serious. This infection can cause severe damage to the inner lining of the heart and to the valves. The infection can be treated in most cases with strong antibiotics given through an IV over the course of several weeks. However, heart damage may occur before the infection can be controlled. Consult your child's physician for more information.