Endocarditis is an inflammatory disorder of the heart valves or the mural endocardium (the innermost layer of the three layered walls of the heart). It can be caused by bacterial infection, or by other means. Libman-Sacks endocarditis is nonbacterial and is caused by systemic lupus erythematosus. In bacterial versions of this disorder, valvular lesions from previous infections or congenital heart disease are the predisposing factors.