Total drainage of pulmonary veins into the right atrium.

Anomalies of the pulmonary venous return are uncommon, particularly malformations with total drainage of the pulmonary veins directly into the right atrium. Brody (1942) reviewed the literature on anomalous pulmonary venous drainage, dealing with 106 cases, including four personal ones. Further necropsy reports have since been presented by Vass and Mack (1949) and Smith (1951), the latter also noting details of additional cases in the literature. Recent case reports by Johnson and McRae (1948), Dotter, Hardisty and Steinberg (1949), Knutson, Taylor, Pruitt and Dry (1950), Friedlich, Bing and Blount (1950), Grishman, Brahms, Gordon and King (f951), and Muller (1951) have dealt with patients diagnosed during life by means of angiocardiography and cardiac catheterization. Out of a total of 182 cases of anomalous pulmonary veins thus reported in the literature, 30 showed total anomalous drainage of the pulmonary veins into the right atrium or the coronary sinus. The embryology of total pulmonary drainage into the right side of the heart has been discussed by Brody (1942) and by Brantigan (1947). Taussig (1947) has described fully its clinical aspects. The systemic circulation can only receive oxygenated blood from the right side of the heart via a patent foramen ovale. As the right side of the heart receives blood from both the systemic and pulmonary circulations, pulmonary congestion usually results from the excessive pulmonary blood flow. As suggested by Brody, decompensation in these cases presumably occurs with the gradual narrowing of the foramen ovale and the obliteration of the lumen of the ductus arteriosus, thus precipitating cardiac failure. The electrocardiogram is helpful, for there are few other congenital heart lesions without cyanosis and frequently without a murmur, showing right axis deviation on the electrocardiogram. Partial anomalous venous drainage of the pulmonary veins is encountered occasionally in adults without symptoms, whereas total anomalous venous drainage is usually fatal in the first six months of life. Interest in this malformation, however, is increasing because of the possibilities of diagnosis during life and of surgical treatment. Muller (1951) has reported a successful operation on a 4-year-old girl with complete transposition of the pulmonary veins. Anastomosis between the left auricular appendage and pulmonary vein resulted in the disappearance of cyanosis and the ability to assume normal activities. Muller also performed a similar operation on an adult woman, but she died shortly afterwards. It is probable that earlier diagnosis by cardiac catheterization and angiocardiography will be needed for reparative surgery to be successful. Cardiac catheterization will show an oxygen content of the blood in the right auricle higher than that in the superior vena cava, and also the catheter may enter the pulmonary vein directly from the right auricle. The oxygen concentration of the blood in the femoral artery will be equal to that in the right side of the heart where there is total anomalous drainage, but will be higher if the anomalous drainage is only partial. The following case, in which all four pulmonary veins entered the right atrium directly, presented the usual features of this malformation.