Endocarditis, or infective endocarditis, occurs when the inner lining of the heart (the endocardium) or the heart’s valves become infected by bacteria or other germs. The bacteria that cause endocarditis typically spread through the bloodstream from the mouth, from infected foreign bodies such as needles, or from another part of the body to the heart.

Endocarditis is more likely to affect those who have a previously damaged heart valve, an artificial heart valve or other heart disease or congenital defects. It can occur in people with otherwise healthy hearts as well. 

Endocarditis may occur in children who are born with a heart defect. It tends to occur in association with some congenital heart conditions, such as aortic stenosis or patent ductus arteriosus, more than with others. 

According to the American Heart Association, an estimated 29,000 cases of endocarditis are diagnosed each year among adults and children.

Routine antibiotic use prior to dental and gastrointestinal procedures (prophylaxis) is no longer recommended except for a few exceptions. Your doctor can help to determine whether you need to continue to take antibiotics. Additional antibiotic use for routine infections is not necessary to prevent the development of endocarditis. 

Symptoms of Endocarditis

• Persistent or recurring high fever
• Fatigue and shortness of breath
• Skin rash

Progression and Possible Complications of Endocarditis

If endocarditis is not treated, it can cause permanent damage to the heart valves and other heart structures. Heart valves that become damaged may not work as well as they should to keep blood moving through and out of the heart in one direction. A damaged valve may either allow blood to “leak" backward, or it may become narrow, reducing blood flow through the heart and into the body. Ultimately, damage to the heart valves may lead to heart failure, a condition in which the heart is unable to supply the body with enough blood. If the valve damage is too severe and cannot be repaired, the valve may have to be replaced surgically.

In rare situations, a piece of the infection (vegetation) may break off and travel to the lungs or other parts of the body. If it travels to the brain, it may result in a stroke.

Treatments for Endocarditis

Oftentimes, the piece of infection (vegetation) may be seen by an echocardiogram. A more detailed echocardiogram, called a transesophageal echocardiogram, may be helpful in making this diagnosis. However, an echocardiogram may not be able to see all infections. Multiple blood cultures are usually necessary to make the diagnosis of infective endocarditis. Prompt treatment with proper antibiotics may reduce the possibility that endocarditis will cause significant damage to the heart valves.  

Treatment may include a long course of antibiotics delivered via an IV (intravenous). Surgical repair or replacement of damaged cardiac valves may also be necessary in severe cases.