An index of valvular regurgitation from a radionuclide bolus.

Mitral and aortic regurgitation was assessed from analysis of activity-time curves from right and left ventricles following the intravenous bolus injection of 99Tcm-labelled human serum albumin. The differences in the initial arrival times and the mean transit times for the ventricles were combined to provide an index of regurgitation. The mean index for 18 patients with good ventricular function and no regurgitation was -0.07 +/- 0.55 (SD) seconds. This was not significantly different from the mean value of 0.39 +/- 1.22 s obtained for 9 patients with left ventricular failure but no regurgitation. The indices for 16 patients with mitral or aortic regurgitation agreed well with the severity as assessed by contrast angiography. The mean indices for the mild, moderate and severe regurgitation groups were 2.62 +/- 1.13 s, 5.30 +/- 3.05 s and 10.15 +/- 3.62 s respectively.