How to distinguish between innocent and pathologic murmurs in childhood.

While the distinction between innocent and pathologic murmurs may be readily made in most cases, the ability to clearly define and categorize the innocent murmur by precise criteria is most helpful in identifying those patients who may have more subtle or early manifestations of a pathologic condition. To this end, the author discusses the definition and classification of murmurs, how to evaluate a murmur, classification and features of innocent murmurs, differential diagnosis of the innocent murmur, features of pathologic murmurs, use of noninvasive laboratory studies in diagnosis, and management of the child.