Bacterial Endocarditis

What is bacterial endocarditis?

Bacterial endocarditis is an infection of the inner lining of the heart chambers and 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.

How does the infection occur?

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

A normal heart has a smooth lining, making it difficult for bacteria to stick to it. However, persons with congenital heart disease may have a roughened area on the heart lining caused by pressure from an abnormal opening or a leaky valve. Even after surgery, roughened areas may remain due to scar tissue formation or patches used to redirect blood flow. These rough areas inside the heart are inviting, opportune places for bacteria to build up and multiply.

How does the bacteria get inside the body?

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

• 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, the gastrointestinal tract, or the urinary tract

• Gallbladder or prostate surgery

Who is at risk for bacterial endocarditis?

Individuals with congenital heart disease (CHD) may be at increased risk of developing an infection inside the heart. There is greatest risk in those with chronic cyanotic heart conditions and/or pulmonary hypertension/Eisenmenger’s syndrome. Other congenital conditions that remain at risk are those with residual defects causing turbulent blood flow through heart chambers and/or areas of surgical repair with artificial materials, such as patches or valve replacements.

Extensive review of research by the AHA's Endocarditis Committee and international experts developed new guidelines for prevention of bacterial endocarditis in 2007. The new guidelines have also been endorsed by the Infectious Diseases Society of America, the Pediatric Infectious Disease Society, and the American Dental Association.

Previously all people with CHD received antibiotics before dental and invasive procedures to prevent endocarditis. The new guidelines, however, require antibiotics prior to dental procedures only for cardiac conditions associated with the highest risk of complications from endocarditis. You will need to discuss your child’s congenital condition with his or her health care provider to determine if your child needs antibiotic prevention.

Note that antibiotic prophylaxis may change if your child has more surgery or any new concern with his or her heart condition. Some of the simple patch or valve repairs only require antibiotics for the first six months after surgery until the artificial material undergoes endothelialization, a process in which natural tissue grows over the artificial material and makes it smooth.

Antibiotic prophylaxis is now recommended only for the following cardiac conditions:

• Prosthetic (artificial) heart valves

• A previous history of endocarditis

• Congenital heart disease only in the following categories:

  • Unrepaired cyanotic congenital heart conditions, including those with palliative shunts and conduits

  • Congenital heart conditions completely repaired with prosthetic material or device, whether placed by surgery or catheter intervention, during the first six months after the procedure

  • Repaired congenital heart conditions with residual defects at the site or adjacent to the site of a prosthetic patch or device (which inhibit endothelialization)

• Cardiac transplantation recipients with cardiac valvular disease

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

How is bacterial endocarditis diagnosed?

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.

How is bacterial endocarditis prevented?

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.

According to the AHA guidelines, prior  to procedures that put your child at risk, one dose of an antibiotic should be 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 give prescriptions for the antibiotics to you.

Treatment for bacterial endocarditis

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

• Your child's age, overall health, and medical history

• Extent of the infection

• 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. Surgery may be required to repair or replace a damaged heart valve. Consult your child's health care provider for more information.