2-dimensional echocardiographic appearance of complete left-sided juxtaposition of the atrial appendages.

This report describes the 2-dimensional (2-D) echocardiographic appearance of left-sided juxtaposition of the atrial appendages (JAA). From January 1, 1978, to June 30, 1979, 2 infants had the diagnosis of left-sided JAA at autopsy. Both patients had previously been examined by subxiphoid 2-D echocardiography. On review of these studies, the septum secundum was found to be oriented posteriorly in the transverse view of the atria. From July 1979 to June 1981, prospective evaluation of all infants for the presence of this finding revealed 2 more patients. Left-sided JAA was confirmed at surgery in 1 case and by selective right atrial angiography in the other. The diagnosis of left-sided JAA has important implications for both atrial baffle operations and for the Fontan procedure.