THE DIAGNOSIS OF CORRECTED TRANSPOSITION OF THE GREAT VESSELS

Abstract

In a post-mortem study of anatomical, angiocardiographic, and catheterization data, we have compared two cases representative of the two principal groups of corrected transposition of the great vessels with two control cases that might be confused with them, and have applied this information, together with some obtained from the electrocardiogram, to the diagnosis in vivo of these congenital malformations. The following observations were made. (a) The P waves of lead I are of aid in determining the position of the anatomical atria. (b) The diagnosis of transposition may be suspected from the frontal X-rays taken during catheterization or angiocardiography if one of the great vessels is seen arising in a striaght line from its ventricle or if both of the great vessels are seen to be parallel and uncrossed. (c) The diagnosis of transposition can be made with certainty from the lateral films if the aorta is seen arising anterior and parallel to the pulmonary trunk. (d) If the diagnosis of transposition is certain from the lateral views, reference to the frontal views will localize the anatomical ventricles. Since the aorta is anterior it must arise from the anterior ventricle and this is always the anatomical right ventricle which will be on the right or left according to the position of the aorta. The pulmonary trunk is always posterior and arises from the posterior ventricle which is always the anatomical left ventricle therefore the anatomical left ventricle will be localized on the right or left side according to the position of the pulmonary trunk. The frontal views will also show the position of the apex and the situation of the viscera. By combining the information obtained with these studies, it is possible to localize accurately all the chambers of the heart and made the final diagnosis of corrected transposition of the great vessels in each of its varieties.