THE SURGICAL ANATOMY OF VENTRICULAR SEPTAL-DEFECTS WITH UNIVENTRICULAR ATRIOVENTRICULAR CONNECTION

Hearts that do not possess one-to-one connections at the segmental jun ctions almost always produce a univentricular atrioventricular connect ion. One ventricle is usually large and dominant and the other small, lacking one or two of its components. The ventricular septal deficienc y forms part of the circulatory pathway. We take the stance that only hearts that possess a truly solitary ventricular chamber are univentri cular. They cannot have a ventricular septal defect, and so are exclud ed from this study. This review, therefore, is concerned with the morp hology of septal defects in hearts in which both atrioventricular junc tions are connected exclusively to a dominant left or a dominant right ventricle, and those lacking one atrioventricular connection, where t he remaining valve is connected to a dominant ventricle. This morpholo gy in the absence of one atrioventricular connection can be modified w hen there is overriding of the solitary atrioventricular valve. The ve ntricular septal defects are analyzed and categorized for the various groups, and the position of the conduction axis is described for the w ell-recognized entities.