Comparison of surface counting computer values with dye dilution values of cardiac output

Twenty- six cardiac output determinations on ten normal subjects were performed to compare cardiac output values determined with a real time semiautomatic radioisotope surface counting system to values determined nearly simultaneously by the more conventional dye dilution technique. A difference analysis indicated that the radioisotope method yielded slightly larger values for cardiac output with a mean difference of 0. 6 liters/min.