Dye-Dilution Curves from Left Heart and Aorta for Localization of Left-to-Right Shunts and Detection of Valvular Insufficiency

Abstract

Indicator dilution curves from a peripheral artery were recorded with a cuvette densitometer following the injection of blue dye into the left heart or aorta in 33 patients including both normals and those with a variety of left-to-right shunts. The rapidly descending limb of the dilution curves were interrupted by shunted blood when dye was injected proximal to the site of the shunt. Curves distal to the shunt were of normal contour. This method has proven to be of value in the precise localization of left-to-right intra or extra-cardiac shunts, often impossible by conventional techniques.