Dye Dilution Curves in Cyanotic Congenital Heart Disease

Abstract
Use of cuvette and earpiece oximeters facilitates the recording of the immediate dilution pattern of the dye T-1824 (Evans blue) in the arterial blood. In patients with venoarterial shunts the pattern of the dilution curves differs from normal. Quantitative analysis of such curves from patients with cyanotic congenital heart disease has been undertaken to establish the proportion of blood which bypassed the pulmonary circulation. The results obtained have been compared with estimates of the volume of the shunt from cardiac catheterization data and related to the arterial oxygen saturation.