Editorial: Connexions, relations, discordance, and distorsions.

It is impossible to discuss complex cardiac anom-nomenclature based upon connexions is both more alies without clearly differentiating between meaningful and more helpful than one based upon relations and connexions.Relations describe broad relations.This holds good not only for the embryo- spatial interrelationships of two cardiac structures.logist, but for the cardiologist, surgeon, radiologist, In contrast, connexions specifically state the fashion and pathologist.in which two structures are connected one to the In this issue of the British Heart J7ournal, de la other irrespective of their relations.Connexions Cruz and her colleagues (1976) propose a nomen- and relations may be, and indeed usually are, the clature together with rules for diagnosis which are same.Unfortunately this is not always the case, based entirely upon relationships.If these rules are which is precisely why we prefer the concept of applied to the two cases quoted above, then connexions.To take two examples; firstly, it is diagnoses of, firstly, a discordant atrioventricular possible for the normally situated right atrium to be relation and, secondly, of normally related great normally connected to the morphological right arteries without transposition would be made.ventricle, but for this right ventricle to be left sided Such diagnoses are not only misleading, but could (Anderson, Shinebourne, and Gerlis, 1974).Thus be positively dangerous in a clinical context.the connexions are normal, but the relations of the It is also suggested that viscero-atrial situs should ventricles are clearly abnormal, since they are be established from hepatic and inferior vena caval spatially inverted.Secondly, it is usual for the position, and ventricular position from examination aorta to be posterior and right sided with relation of the relationships of the infundibula and great to the pulmonary artery in a patient with situs arteries.In order to establish the latter relationsolitus and normally connected ventricles.However, ships, de la Cruz et al. ( 1976) provide complex and it has been shown that the normally related aorta in lengthy 'rules'.This seems to us to be using a this situation can take origin from the right ventricle sledgehammer to crack a nut.and not the left (Van Praagh et al., 1971;Wilkinson Angiocardiographically, ventricles need only be et al., 1975).Using a relations concept, it is not pos-defined in terms of their intrinsic qualities.With the sible to describe this connexion as transposition.possible exception of coronary arteries, it is actually However, unequivocally the ventriculo-arterial con-misleading to refer to other structures.One of us nexionisone oftransposition (VanPraagh etal., 1971; (F.J.M.) has worked in a centre in which, for the Wilkinson et al., 1975).It is the intracardiac con-past five years, all symptomatic complex 'transposinexions which are determined by embryogenesis.tions' and 'malpositions' of appropriate age have These in turn determine the haemodynamic condi-been referred for corrective surgery.Ventricular tion of the patient and the corrective surgery which localization has been carried out solely by examinamay be required.In contrast, relations may be tion of the diastolic shape and trabecular pattern affected by multiple extracardiac events, and by after injection of contrast medium into both venrotation of the heart following completion of its tricles, and atrioventricular connexion established normal development.Thus, we believe that a by inspection of the atria, catheter course, and atrioventricular valves.No error in these respects 1R.H.A. is a British Heart Foundation Senior Research has been made in over 1300 cases studied.This Fellow.experience is not regarded as anything special, but