Causes, incidence, and risk factors Endocarditis can involve the heart muscle , heart valves, or lining of the heart. Most people who develop endocarditis have underlying valvular heart disease . Injection drug use is a common risk factor for developing endocarditis.
Bacterial infection is the most common source of endocarditis.
However, it can also be caused by viruses, fungi, or other microorganisms. In some cases, no causative organism can be identified. Continued medical follow-up is advised for people with a previous history of endocarditis. Signs and tests A history of congenital heart disease , intravenous drug use, or chronic localized abscess or infection, raises the index of suspicion. The examiner may detect a new heart murmur, or a change in a previous heart murmur.