Hi doctors, was just wondering what is bacterial endocarditis?

Heart infection: Subacute infective endocarditis is an infection of the endocardial surface (lining) of the heart, which may include heart valves, the walls, or a septal defect. People at greatest risk of endocarditis have a damaged heart valve, an artificial heart valve or other heart defects. Iv drug abusers are at great risk. Symptoms may be vague and diagnosis is often delayed. Treatment is essential.