An unusual cause for a continuous murmur.

A continuous murmur like that of a persistent ductus arteriosus produced by a stenosed branch of a pulmonary artery with a post-stenotic dilatation is presented in the following case. Other abnormalities included a hypoplastic left lung, atrial septal defect, ventricular septal defect, and an absent left pulmonary artery. The literature on congenital heart disease contains increasing numbers of case reports of the congenital absence of a pulmonary artery, and may be associated with either a normal heart or other congenital cardiac abnormalities. The number of cases diagnosed without operation has increased with the use of angiocardiography and cardiac catheterization. These aids may, however, on occasion be misleading, as is shown in this case. Physical and operative findings were thought worthy of reporting, not only because of the mistaken diagnosis but also because of the unusual cause of a continuous murmur simulating a persistent ductus arteriosus.