Congenitally corrected transposition with normally positioned atria, straddling mitral valve, and isolated posterior atrioventricular node and bundle.

A heart is described with congenitally corrected transposition of the great arteries, normally positioned atria, and a straddling mitral valve. Instead of an anteriorly positioned atrioventricular node, a regularly positioned posterior node and bundle were observed. This observation has important clinical and surgical implications and underlines that close inspection of the alignment of atrial and ventricular septa during operations is mandatory.