Bacterial endocarditis is a potentially fatal infection in the lining of the heart chambers and valves. This infection can occur when germs enter the bloodstream through a break in the skin and settle on abnormal or damaged heart valves or on damaged lining in the heart chambers. Bacteria for this type of infection is readily available since it normally lives in places like the mouth, nose or skin. Patients are likely to be more vulnerable to endocarditis during a medical procedure that causes a break in the skin such as surgery, dental procedures, or minimally invasive procedures like a heart catheterization. Patients who may be at higher risk of developing endocarditis are those with artificial heart valves, heart valves that did not develop properly prior to birth (congenital defect), a history of endocarditis, valves that were damaged by heart disease such as rheumatic fever, or a heart transplant.