The aortic ejection fraction: A new technique for diagnosing aortic insufficiency

Pulsations of the ascending aorta during fluoroscopy in patients (pts) with aortic insufficiency (AI) have been described. The authors observed a similar phenomenon in pts undergoing scintiangiography who have documented AI. This paper describes a technique to validate and quantitate this observation. The authors studied 17 patients with AI documented by cardiac catheterization and 14 subjects of a demographically matched control group with no evidence of AI. First pass studies were acquired in the RAO 150 projection after a bolus of 20 mCi of Tc-99m pertechnetate. After framing, identical ROI's were placed over the proximal aorta during systole and diastole excluding activity of the pulmonary arteries and/or atria. An aortic ejection fraction (AEF) was determined. The calculated AEF data was correlated with the presence or absence of AI. The mean AEF from the group of 17 patients was 26.9 +- 7.0, while the mean for the non AI group was 12.0 +- 6.5. These are statistically different at the P < .01 level. An AEF of 18 optimally separates the 2 groups with a sensitivity, specificity, and accuracy of 88%, 86%, and 87% respectively. Preliminary data demonstrates a mean reduction in AEF of 14.6 units in the AI patients who, to date, have undergone aortic valve replacement. Initial data suggests that this technique, using the AEF, may be able to identify patients with AI without the task of isolating the right ventricle