Validation of Fourier amplitude ratio to quantitate valvular regurgitation.

It has previously been shown that patients with valvular regurgitation can be identified by the ratio of left and right ventricular amplitude values obtained from first harmonic Fourier analysis of the gated blood pool scan. The present study was designed to validate the accuracy of this technique for quantifying the amount of valvular regurgitation. In a blinded analysis of 19 patients who underwent cardiac catheterization, there was a close correlation between the radionuclide and hemodynamic determination of the amount of regurgitation (r = 0.84). The interobserver agreement for calculating the radionuclide data was also high (r = 0.88). These results suggest that the Fourier ventricular amplitude ratio is an accurate and reproducible technique for quantifying valvular regurgitation by gated blood pool scanning.