Endocarditis is an inflammation of the inner layer of the heart. Endocarditis most often affects the heart valves. The heart valves are a part of the human body that does not get blood. This is odd because they are a part of the heart itself. Because of this, if one of the valves gets infected with bacteria or protozoa, the body can not defend itself against those bacteria. This can cause the valve to not work the way it should.