1087 quantitative changes in intracardiac flow parameters during hemodialytic sessions

Abstract Background Hemodialysis sessions exert an acute impact on cardiac geometry and mechanics. The recent development of quantitative measurement of intracardiac fluid-dynamics offers a new opportinuty to better understand the fine changes in intracardiac cardiac hemodynamics associated with hemodialysis sessions. Our aim was to assess the impact of an hemodialytic session on intracardiac flow dynamics. Methods We included 26 consecutive patients on chronic hemodialysis in clinically stable phase. They underwent echocardiography including intracardiac fluid-dynamic analysis by Color Vector Flow Mapping (Hyperdoppler) before and after a single dialysis session. Patients with hemodynamically relevant valvular disease were excluded. A complete fluid-dynamics evaluation included the measurement of multiple parameters such asvortex area (VA); vortex length (VL); vortex depth (VD). Bland Altman Plot has been used to assess intra and inter-observer variability. Changes in fluidodynamics after dialysis sessions were tested using the Wilcoxon matched-pairs test. Results Mean Vortex Area (VA) (p=0.034), Vortex Depth (VD) (p=0.024) and Vortex Length (VL) (p=0.037) were significantly reduced after the dialysis session. A similar trend towards the reduction of Direct Flow (DF) parameter after the session was found, which was significantly larger for patients with larger baseline left ventricular (LV) end-diastolic diameter (r=0.446; p=0.037). On the other hand, mean Vortex Intensity (VI) was significanlty increased after dialysis (p=0.046). Among energy parameters, the intradialytic change in Kinetic Energy Fluctuation (KEF) (r=0.4; p=0.058) and Shear Stress Fluctuation (SSF) (r=0.435; p=0.038) were most closely correlated with intradialytic weigth change. Some fluid-dynamic parameters had similar trends of intradialytic change, with stonger correlations among geometric parameters. Delta changes in VA were closely related to changes in VI (p<0.001) or LV (p<0.001). VI was also correlated with VL (p<0.001) and with Kinetc Energy Dissipation (KED) (p=0.030), which was also correlated with VL (p=0.044). KEF was correlated with KED (p=0.001) and SSF (p=0.022). Finally, chenges in SSF were correlated with those in Flow Force Parameter (p=0.033) and Flow Force Angle (p=0.034), that were very closely correlated each other (p<0.001). Discussion This is the first study assessing the impact of hemodialytic sessions on intracardiac flow dynamics. Measurement of hyperdoppler indices on hemodialysis chair was feasible and reliable in the whole population. Our results uncovered quantitative chenages of echocardiographic parameters of vortex geometry and energy during hemodialysis.