Endocarditis is an inflammation or infection of the inner surface of the heart (the endocardium). It occurs when bacteria enter the bloodstream and attach to a damaged portion of the endocardium or abnormal heart valves. But it may also develop on devices implanted in the heart, such as artificial heart valves, pacemakers, or implantable defibrillators.
When normal blood components, like fibrin and platelets, stick to the bacteria, the resulting buildup is called a vegetation.
Endocarditis can limit the heart’s ability to efficiently pump blood. Damaged infected valves can cause severe leaking (regurgitation) of blood back through the valve(s).
In addition, small pieces of the vegetation can break off and travel through the blood vessels to other parts of the body and cause problems like stroke or tissue damage, when they lodge and block blood flow to the tissues downstream.