Radiographic Findings in Anomalous Muscle Bundle of the Right Ventricle An Analysis of 15 Cases

Clinical and radiographic findings in 15 cases of anomalous muscle bundle obstructing the right ventricle are presented. Chest radiographs were normal in 8 cases and suggested ventricular septal defect in 5 and tetralogy of Fallot in 2 cases. Pressure gradients ranged from 15 to 101 mm Hg. At right ventriculography the AMB usually appeared as a mass arising near the apex of the right ventricle and inserting near the crista supraventricularis. Anomalous muscle bundle clinically simulates ventricular septal defect and tetralogy of Fallot. Preoperative recognition of this condition is important.