Differential Diagnosis of the Taussig-Bing Heart from Complete Transposition of the Great Vessels with a Posteriorly Overriding Pulmonary Artery

A CCORDING to a recent review article,1 J ~ there seems to be some disagreement about what constitutes a transposition of the Taussig-Bing variety, what the criteria for its diagnosis are, and with what certainty this diagnosis can be made during life. There is, however, general agreement that in the eya-iiotic group of congenital heart disease, the various forms of transpositions of the great vessels constitute a well-defined entity as far as their physiology is concerned. The hemody-namics are characterized by the separation of the 2 circulations and the amount of blood-mixing that is allowed between them by the number and size of the additional lesions. In regard to the anatomic arrangement which may be found in transpositions of the great vessels, it is well known that the degree of displacement of the aorta and pulmonary artery and their relation to each other may vary considerably from case to case. This was early recognized by Peacock,2 Rokitansky,3 Lochte,4 Spitzer,5 and Pernkopf6 and was clinically analyzed by Taussig.7 Among these various forms of transpositions, the Taussig-Bing transposition is a well-described clinical and anatomic entity. Physiologically, how-ever, the Taussig-Bing transposition is not so fundamentally different from the other types of transpositions as it is anatomically. This is notably true of the other group of transposi-tions with an overriding pulmonary artery and also of the complete transpositions with large ventricular septal defects. This physio-logic similarity may account for the difficulty in the differential diagnosis. Although there has been no further cas