Infective Endocarditis: Forms

-Subacute: aggressive; develops insidiously & progresses slowly (weeks-months). Usually no source of infection or portal of entry evident (streptococci most common cause). - Acute: develops abruptly & progresses rapidly (days). Evident source of infection or portal of entry ( s.aureus, group A strep, pneumococci, gonococci). If massive bacteria - can affect normal valve, - Prosthetic: develops within1 year after valve replacement; aortic>mitral . Affects mechanical and biprosthetic valves equally