Comparative Evaluation of Thermodilution and Gated Blood Pool Method for Determination of Right Ventricular Ejection Fraction at Rest and during Exercise

Background: Since the development of a Swan-Ganz thermodilution ejection fraction catheter several studies have been published which compare this technique for obtaining right ventricular ejection fraction (RVEF TD ) with alternative methods. However, the reliability of RVEF TD measurements under exercise conditions remains undetermined. Therefore, the aim of the present study was a comparative evaluation of RVEF TD with the established gated blood pool method (RVEF GBP ) under exercise conditions. Methods and Results: Twenty-two patients with different cardiac diseases underwent right heart catheterization, including RVEF TD and simultaneous RVEF GBP determination at rest and during supine bicycle exercise. Linear regression analysis showed a significant correlation between RVEF TD and RVEF GBP at rest (r = 0.73, p ≤ 0.0005) and during exercise (r = 0.74, p ≤ 0.0005). A Wilcoxon analysis showed a high probability of agreement of RVEF TD and RVEF GBP at rest and exercise (level of significance for error of the 0 hypothesis of 95.9/73.3%). Conclusion: The thermodilution ejection fraction catheter provides a useful device for reliable, repetitive and safe RVEF measurements, not only at rest but also under exercise conditions. This seems to be clinically important, because by it means RVEF, as a sensitive parameter of primary or secondary right ventricular dysfunction, can be determined in the course of standard right heart catheterization.