The Use of an Oximetrically Determined Circulation Time from the Right Ventricle to the Ear in Congenital Heart Disease

Abstract

Evans Blue (T-1824) was injected into the right ventricle through a cardiac catheter and the time of the arrival of dye at the ear was measured with an oximeter. This circulation time appeared to indicate reliably the presence of venoarterial shunting through an over-riding aorta. The difficulties ordinarily encountered in positive identification of this defect are discussed. The importance of the identification, particularly with regard to the differential diagnosis between tetralogy of Fallot and pulmonary stenosis with an interatrial communication, is stressed.