Abstract
Sequential rest-exercise gated blood pool scans were performed to evaluate left ventricular function in seven patients with aortic regurgitation (four males and three females, mean age 38±16), to evaluate the use of this test to provide information helpful in determination of therapy. Exercise was performed with a bicycle ergometer to symptom-limited maximum. Ejection fraction (EF), regurgitant fraction, and pulmonary blood volume were determined on two occasions for each patient (4–16 months apart). Mean rest and exercise EF did not change significantly with time. Group mean regurgitant fraction did not change significantly, whereas pulmonary blood volume increased significantly. However, three patients had a decrease in rest EF on study two, diminished left ventricular reserve function determined by a decrease in EF on exercise, and an increase in pulmonary blood volume on study two without a significant change in exercise regurgitant fraction on the second gated blood pool study, and were recommended to have a cardiac catheterization even though they were relatively asymptomatic. These patients were found to have significant aortic regurtitation and had subsequent aortic valve replacement. In conclusion, patients with aortic valvular disease can be followed with routine rest and exercise gated blood pool scans to determine pathophysiological changes that result from the volume overload; these parameters can be used as a guide to type of therapeutic intervention.
