Abnormalities of the main systemic and pulmonary veins are arousing increasing interest. The object of this paper is to review our experience of 46 cases of the left-sided superior vena cava, including 4 examples of the much rarer condition where the inferior vena cava is absent. We wish also to discuss the type of cases in which these occur and their clinical significance.Abnormal drainage of the pulmonary veins has been discussed in several recent papersdrainage into the left superior vena cava by Snellen and Albers (1952), Gardner andOram (1953), and Whitaker (1954), and drainage into the right atrium and the right side generally by Brody (1942), Smith (1951), Edwards (1953), and Swan et al. (1953). These groups will not, therefore, be included here, especially as we have seen few examples of the former. EMBRYOLOGYThe relevant embryology will be reviewed shortly to help in understanding these abnormalities. The Left-sided Superior Vena Cava. At one stage in the formation of the human embryo the sinu-atrial chamber becomes differentiated into the sinus venosus and the atrial chamber; and the septum dividing the latter into the right and left parts is formed in such a way that the sinus venosus communicates with the right part only. The sinus venosus lies transversely, dorsal to the atrial part of the heart, and its lateral parts are known as the horns, into each of which a duct of Cuvier opens. This is formed by the union of an anterior and a posterior cardinal vein, the former of these draining blood from the cephalic end and the latter from the caudal end of the embryo (Fig. 1). As development proceeds the heart as a whole moves caudally into the thorax

No abstract

Seven patients with normal specialized conduction system and three patients with the Wolff-Parkinson-White (WPW) syndrome were studied using programmed stimulation of the feart before and after the administration of intravenous disopyramide. The principal effect of this drug was to prolong the effective refractory period of the atria and ventricles, and to prolong the effective refractory period of the anomalous pathway in the WPW syndrome. In addition, it prolonged the conduction time in the anomalous pathway in the WPW syndrome. These findings suggest that disopyramide would be a useful and safe drug in the management of certain atrial and ventricular arrhythmias and in the management of the Wolff-Parkinson-White syndrome with atrial fibrillation.

No abstract

No abstract