Documentation of tricuspid regurgitation by radionuclide angiocardiography.

Review of the radionuclide cardiac angiograms of 82 patients studied during the past year showed reflux of activity down the inferior vena cava in 7, all ofwhom had clinical evidencefor or clinical conditions associated with tricuspid regurgitation. Analysis of theflow of the radioactive bolus through the cardiac chambers demonstrates that the inferior vena cava fills only after activity enters the right ventricle and that filling is most pronounced during ventricular systole. In one case of right-sided endocarditis in which the characteristic