infectious endocarditis, endocarditis caused by infection with microorganisms, especially bacteria and fungi. It was formerly classified according to course as acute and subacute: the acute form is usually caused by staphylococci, pneumococci, gonococci, or streptococci, involves a normal heart valve, and has a short history and rapid course; the subacute form usually is caused by viridans or fecal streptococci or fungi, affects damaged heart valves, and has a prolonged course. Because underlying causes and available therapies have changed, this division has little current clinical validity and has been largely replaced by classification on the basis of cause or underlying anatomy.
