Radionuclide measurements of left ventricular function. Their use in patients with aortic insufficiency.

Radionuclide angiocardiography was used to measure left ventricular ejection fraction and end-diastolic volume while at rest and during exercise in 20 patients with severe aortic insufficiency. A second study was performed one year later in ten of these patients who did not undergo aortic valve replacement and in ten patients one year after operation. In patients without aortic valve replacement, the maximum ejection fraction achieved during exercise was 63% +/- 9% during the first study, and decreased to 57% +/- 9% after one year without a change in ejection fraction while at rest. No change in end-diastolic volume either while at rest or during exercise occurred during that period of time. In patients undergoing aortic valve reconstruction, the most striking change after one year was a decrease in end-diastolic volume from 296 +/- 107 to 148 +/- 37 mL at rest and from 306 +/- 92 to 155 +/- 38 mL during exercise. Ejection fraction increased by 10% at rest and 12% during exercise. Therefore, medically treated patients with aortic insufficiency lost the ability to increase ejection fraction during exercise without alteration of the ejection fraction while at rest over the one year of study. In contrast, aortic valve reconstruction resulted in a decrease in end-diastolic volume and an increase in ejection fraction during rest and exercise.