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.