CONGENITAL HEART DISEASE: MEASUREMENTS OF THE CIRCULATION

CLINICAL AND EXPERIMENTAL DATA  The cyanosis of congenital heart disease is usually associated with a considerable degree of unsaturation of the arterial blood. In these cases, as noted by Lundsgaard and Van Slyke,¹ either (a) the blood that passes through the lungs is insufficiently saturated with oxygen, owing to some pulmonary defect, or (b) there is a shunting of some venous blood from the right side of the heart into the systemic aorta without its having passed through the pulmonary alveoli.Some years ago Haldane and Douglas² placed a patient with cyanotic congenital heart disease in an atmosphere high in oxygen and noted that the cyanosis did not clear; they inferred that the defective aeration of the blood was not due to pulmonary insufficiency. On the other hand, Campbell, Hunt and Poulton³ tried the same procedure with one of their patients having congenital heart disease, and found that the arterial