The Use of Ascorbate Dilution Curves in Cardiovascular Diagnosis

Abstract

The instrumentation and clinical applications, in this laboratory, of Clark's sodium ascorbate dilution technic are described. With this method the sensing device, a platinum electrode, is introduced directly into the blood stream, and a reducing agent, sodium ascorbate, is used as the indicator. Time-concentration curves may be obtained without the withdrawal of blood. Observations in 90 patients have indicated that the contours of the dilution curves are essentially identical to indocyanine-green dye-dilution curves, except for diminished peripheral recirculation peaks. The ascorbate-dilution technic has been found of particular value when the sensing electrode is incorporated into a cardiac catheter. This method permits injection and sampling of the indicator from the central circulation and greatly facilitates the study of circulatory shunts and of valvular regurgitation.