Aorto-right atrial fistula.

We report a child in whom a fistula connected the descending thoracic aorta to the right atrium. This is a previously unreported cardiac malformation. The patient was initially misdiagnosed as having a patent ductus arteriosus (PDA). On clinical examination and auscultation, the problem was different from PDA in that the continuous machinery murmur was better heard on the right parasternal area and posteriorly on the left. Surgical ligation of the fistula through a left thoracotomy abolished the murmur.