Anomalous muscle bundle of the right ventricle. A report of seven cases.

It was within the last decade that right ventricular outflow obstruction due to anomalous muscle bundle was clearly described as a separate cardiac malformation seven cases of anomalous muscle bundle of the right ventricle were presented, and the diagnosis and surgical indications of this anomaly were discussed. The clinical differentiation of these patients from those with isolated VSD, pulmonic stenosis, and tetralogy of Fallot was not easy. Right ventriculograms that demonstrated the anomalous muscle bundle as a wedge-shaped filling defect are most useful for differentiation. All patients' anomalies were corrected with intracardiac surgery. The postoperative course was very satisfactory and all patients showed complete relief of the obstruction.