Cardiac Malpositions: An Overview Based on Study of Sixty-five Necropsy Specimens

Cardiac malformations associated with cardiac malpositions are so complex that even angiographic studies may not afford as accurate information as direct examination of necropsy specimens. This communication will attempt to outline a systematic approach to cardiac malpositions based upon necropsy studies of 65 cases. Where possible, morphologic features characteristic of the entities are correlated with clinical, roentgenographic, electrocardiographic and catheterization findings. Embryologic considerations are also discussed. The problems of terminology in complex congenital cardiac anomalies, particularly those with abnormalities of position, are well known. For an excellent discussion, the reader is referred to the recent article by Wilkinson and Acerete.5 Rather than creating new terms, the authors selected existing terms which they considered the least ambiguous and least confusing. We have used the selected terms as defined in that article with three exceptions. 1) The asplenia and the polysplenia syndromes are sufficiently distinct to warrant separate categories, rather than grouping them as situs ambiguus. The reasons for this are discussed in the sections dealing with these entities. 2) Transposition herein refers only to transposition of the great arteries as defined by Van Praagh,2 i.e., aorta arising from the morphologic right, and pulmonary artery from the morphologic left, ventricle. 3) We concur with Van Praagh in classifying Taussig-Bing anomaly as a form of double outlet right ventricle with a subpulmonic ventricular septal defect.3