Indexing peak rapid filling velocity to both relaxation and filling volume to estimate left ventricular filling pressures.

Abstract

The peak transmitral velocity/peak mitral annular velocity (E/e') ratio has been used as a left ventricular (LV) filling pressure (LVFP) correlate. However, the E/e' and its changes with haemodynamic alterations have not always correlated with changes in LVFP's. We hypothesized that indexing E/e' to a measure of LV filling volume may enhance the correlation with LVFP and LVFP changes. We summarized previously obtained haemodynamic and Doppler echo data in 137 dogs with coronary microsphere embolization induced-chronic LV dysfunction prior to and following haemodynamic induced alterations in LVFP's. E/e' values were obtained as E*tau where tau is the inverse logarithmic LV pressure decay. E*tau was indexed to LV filling volume by dividing by the diastolic time velocity integral (DVI) and correlated with LV mean diastolic pressure (LVmDP). Similarly, the relationship of E/e' and E/e'/DVI to LV pre A wave pressure was evaluated in 84 patients by invasive haemodynamics and Doppler echo. Combining data from all interventions, LVmDP correlated with E*tau (r = 0.408) but more strongly with E*tau/DVI (r = 0.667, z = 3.03, P = 0.0008). The change in LVmDP correlated with the change in E*tau/DVI (r = 0.742) more strongly than E*Tau (r = 0.187, Z = 4.01, P < 0.0001). In the patient cohort, E/e' was modestly correlated with LV pre A wave pressure (r = 0.301) but more strongly correlated with E/e'/DVI (r = 0.636, z = 2.36, P = 0.0161). Indexing E to both LV relaxation and filling volume results in a more robust relation with LVFP's and with LVFP changes.