Malalignment of the septum primum with abnormally positioned left atrial appendage: unusual combination in a Shone's heart.

This case discusses a Shone's variant with small left ventricle and mitral valve, bicuspid aortic valve, coarctation of the aorta, an unusual arrangement of atrial appendages, and partially anomalous pulmonary venous drainage due to a deviated atrial septum. The left atrial appendage could be directly entered from the right atrium at catheterization, but it was positioned behind the great arteries. The right atrial appendage was normal in origin and orientation. The implications of this anatomy in fetal cardiac development are reviewed.