Abstract

Discrete delicate fibromuscular structures crossing the cavity of the left ventricle were identified on morphological examination in 329 (48%) of 686 hearts from patients of all ages with congenital heart disease, acquired heart disease, or normal hearts. These structures were also present in 151 (95%) of 159 hearts from animals of six species. Cross sectional echocardiographic findings compatible with these structures were obtained in 39 (21.7%) of 179 children reviewed retrospectively and in three of 800 (0.4%) adults studied prospectively. These structures appear to be a normal anatomical finding.