[Innominate vein in a subaortic position. Value of contrast echocardiography using a suprasternal approach].

The innominate vein usually lies superior to the aorta: using a suprasternal approach and an injection of contrast in the left arm, it is the earliest and most cephalad structure to be opacified. The aortic arch, right pulmonary artery and left atrium lie respectively below it. This relationship of these four structures is constant in all arrangements of the great arteries, forming the basis of contrast echocardiographic identification of the great vessels in cases of transposition. A case is reported of an innominate vein, the first structure to be opacified, lying inferior to the aortic arch and above the right pulmonary artery. This anomaly seems to be very rare.