Radiokymography in patent ductus arteriosus.

The introduction of radiokymography dates from the pioneer work of Gott and Rosenthal (1912). The modern multiple slit kymograph was developed subsequently by Stumpf and his coworkers (1934), while later studies were made by Faber and Kjaergaard (1936) and Bordet and Fischgold (1937). In an earlier paper one of us (Wood, 1939) described the kymographic patterns that comprise the borders of the normal cardiac silhouette. In the present study, X-ray kymography has been applied to the diagnosis of patent ductus arteriosus. The development during the past decade of the surgical treatment of the condition has greatly increased the importance of a diagnosis that may be difficult. In some cases the characteristic continuous murmur is not present and according to statistics quoted by Brown (1939) the pathognomonic murmur is absent in more than half of the cases. On the other hand Taussig (1947) claims that the diagnosis is based on the finding of a continuous murmur over the pulmonary area and that unless such a murmur is present the diagnosis cannot be made with certainty. It is when a murmur confined to systole is heard at the pulmonary area that diagnostic difficulties are likely to arise. Differentiation from pulmonary stenosis may not be easy and the possibility that patency of the ductus may be associated with other anomalies has to be remembered. It is an essential part of the diagnosis to exclude associated defects since when these exist ligature of a ductus may abolish an important compensatory mechanism. As exploratory operations are obviously undesirable, no effort must be spared to determine the correct diagnosis. We consider that the radiokymographic appearances which we now present should help to place the diagnosis of patent ductus arteriosus on a secure basis. METHOD OF INVESTIGATION AND RADIOGRAPHIC TECHNIQUE