Prevention of infective endocarditis: the view from the United States.

The American Heart Association's recommendations for the prevention of infective endocarditis were first published in February, 1955, and the most recent (fifth revision) in December, 1984. The somewhat controversial nature of these recommendations reflects several issues, including the degree to which infective endocarditis in man is preventable and the relative safety of alternative regimens. Nevertheless, it is apparent that a reasonable fraction of cases are preventable and that antibiotics for this purpose are appropriate. It is also clear that certain patient groups, i.e. those with prosthetic valves or surgically constructed systemic-pulmonary shunts, are at greatest risk and warrant more intensive, primarily parenteral antibiotic regimens. Particularly controversial are recommendations related to the very large group of patients with mitral valve prolapse. The latest American Heart Association recommendations are presented in detail.