At the time of autopsy of a 39-year-old female who died of complications of systemic lupus erythematosus, several medium-sized vegetations are found on both sides of the mitral valve and tricuspid valve. These cardiac vegetations are most likely the result of
Presence of an anticardiolipin antibody Turbulent blood flow through an incompetent mitral valve Abnormal secretion of a vasoactive amine Bacterial colonization of an abnormal valve