Oximetry in congenital heart disease with special reference to the effects of voluntary hyperventilation

An oximeter has been used to measure the arterial oxygen saturation of patients with a variety of congenital heart anomalies. The effects of exercise and oxygen administration have been of value in ascertaining the presence of a venous-arterial shunt. The rise in arterial oxygen saturation during a vigorously performed voluntary hyperventilation appears to offer a means of gaging the extent to which the pulmonary circulation may be increased; a less than normal increase has only been found in the presence of pulmonic stenosis or in some instances of pulmonary hypertension and a relatively fixed pulmonary resistance. The results of hyperventilation are sufficiently distinctive to be of diagnostic value in cases of Fallot's tetralogy, Eisenmenger's complex, isolated pulmonic stenosis, pulmonic stenosis with intact ventricular septum and patent foramen ovale, and Ebstein's anomaly of the tricuspid valve with patent foramen ovale.