In April 2007, the American Heart Association (AHA) revised its guidelines for antibiotic treatment at the time of dental procedures and other medical situations in which there is a high likelihood of bacteria entering the bloodstream. In general, the AHA guidelines are the “gold standard” in the United States for how physicians and dentists should practice with respect to this important issue of preventing infections of heart valves (endocarditis). A major aspect of the revised guidelines is the recommendation that oral antibiotic therapy is no longer required at the time of dental work or other procedures expected to contaminate the bloodstream with bacteria for patients with mitral valve prolapse or other valve dysfunction, but is still recommended for those patients who have an artificial heart valve. The basis for this decision was not the conclusion that risk of endocarditis is not present in this population at the time of such procedures, but rather that a cumulative risk is also present in association with other routine activities of daily living, such as brushing and flossing teeth and chewing food. In fact, it is considered that the cumulative risk of endocarditis during daily life activities is higher than that associated with a specific dental or other invasive procedure.