At first sight, it would seem that this individual has a usual atrial arrangement, since all the pulmonary veins connect to the left-sided atrial chamber (A and B), while all the systemic veins connect to the right-sided chamber (B and C). Careful examination of the right-sided chamber, however, shows that the pectinate muscles do not extend to the crux, and the appendage has a narrow junction with the smooth-walled body of the atrium. Both appendages are morphologically left.