Quantification of left-to-right shunts using a PO2-electrode cardiac catheter.

A rapid, simple and low-cost method is presented for intracardiac left-to-right shunt quantification in children with congenital heart disease. The percentage of shunt is calculated from data obtained by continuous PO2 measurement during oxygen inhalation, using a nondisposable intravascular PO2-electrode cardiac catheter. These values are compared with those obtained by the dye-dilution method (correlation coefficient r = 0.89) and the Fick method (correlation coefficient r = 0.98). The PO2 measurement proved reliable for small, medium, and large sized shunts.