A Direct Calculation of Hemodynamic Energy Loss in the Presence of Abnormal Aortic Flow

Alex J. Barker¹, Krishna C. Bandi², Julio Garcia¹, Pim van Ooij¹, Patrick McCarthy², James C. Carr¹, S Chris Malaisrie², Michael Markl¹

In this study, the measurement of viscous energy loss, a parameter which is directly responsible for increased cardiac afterload and is independent of pressure recovery effects, was used to quantify LV loading in the presence of aortic valve disease (AVD). A theoretical basis for the technique is presented and applied in-vivo using 4D flow MRI in a range of healthy, dilated aorta, and aortic stenosis (AS) subjects (n=26). Abnormal flow features, combined with systolic flow jets and flow-jet/wall impingement, resulted in statistically elevated energy loss for dilated (0.080.02W, p=0.011) and AS patients (0.810.42W, p<0.001), compared to healthy volunteers (0.050.02W).