Endodermal heterotopia of the atrioventricular node associated with transposition of the great arteries

A 13-year-old girl with surgically corrected complete transposition of the great arteries died suddenly while walking to school. Postmortem examination revealed endodermal heterotopia of the atrioventricular node, a condition not previously associated with transposition of the great arteries. New immunohistochemical observations are described, and the embryogenesis of the condition and its association with complete transposition are discussed.