The significance of the left atrial appendage in rheumatic heart disease.

The possible diagnostic value of an enlarged left atrial appendage (LAA) on the posterior-anterior or right anterior oblique chest film as a means of implicating a rheumatic etiology for mitral valve disease in children was investigated. Chest films were examined without prior knowledge of clinical or laboratory data, and the results were later correlated with this information in 113 children and adolescents. The clinical and laboratory data included application of the modified Jones criteria for the diagnosis of acute rheumatic fever, streptococcal antibody titers and clinical and cardiac catheterization findings. In children with mitral valve disease, our data suggest that as enlarged LAA, especially in the presence of pulmonary venous obstruction, is characteristic of rheumatic heart disease. This finding appears to be particularly useful, in conjunction with streptococcal antibody studies, in distinguishing rheumatic from nonrheumatic patients with mitral insufficiency.