An appraisal of the double indicator-dilution method for the estimation of mitral regurgitation in human subjects

The amount of mitral regurgitation was estimated in 50 patients by an indicator-dilution technic and by the usual clinical, catheterization, operative, and autopsy criteria. There was a good correlation between the two estimates. Patients with significant mitral regurgitation (grade 2 or grade 3) had, with one exception, Q R / Q F ratios above 0.41. There were at least two instances where the calculated Q R / Q F was almost certainly falsely high. It seems likely that these discrepancies are related to the presence of an unusually large volume between the pulmonary artery and the femoral artery.