Preload Dependency of the Time Interval Between the Onset of Mitral Inflow and the Early Diastolic Annular Motion : A Hemodialysis-Related Preload Reduction Study

Background The novel parameter T_<E-E'> which is the time interval between the onset of the early diastolic mitral inflow velocity (E) and the early diastolic mitral annular velocity (E'), is reported to be related to the constant of the left ventricular (LV) relaxation, and T_<E-E'> is also reported to be useful for predicting the LV filling pressure. Methods and Results To investigate the effect of preload reduction via hemodialysis on T_<E-E'>, 28 pairs of echocardiographic evaluations were performed just before and immediately after hemodialysis, including the measurement of the T_<E-E'> as well as measurement of the conventional echocardiographic parameters. The baseline T_<E-E'> was 17.9±28.1 ms, which correlated with the ratio of E/E' (r=0.49, p=0.008). After hemodialysis, T_<E-E'> was shortened to -3.2±34.1 ms, which was a significant change from baseline (p=0.001). Conclusions As T_<E-E'> is a preload dependent parameter, the intravascular volume status should be taken into account when the clinical application of T_<E-E'> is considered as an index of LV relaxation.