The Use of E /Em and the Time Interval Difference of Isovolumic Relaxation ( T IVRT−IVRTm) in Estimating Left Ventricular Filling Pressures

BACKGROUND AND AIMS: The ratio of the transmitral and myocardial early diastolic velocities (E/Em) can be used to estimate LV filling pressures (LVFP). Additionally, the time difference between the onset of E and Em also correlates to LVFP. The aim of this study was to evaluate which of these two indices is the best marker of LVFP in a heterogeneous group of patients during a simultaneous invasive procedure. METHODS AND RESULTS: Thirty two patients were studied. Em and the isovolumic relaxation time (IVRTm) at four segments of the LV were measured using pulsed tissue Doppler echocardiography. Pulsed Doppler echocardiography was used to measure E and IVRT. E/Em and IVRT-IVRTm (T IVRT-IVRTm) were then calculated. Highly significant correlations were found between T IVRT-IVRTm and PCWP at the lateral (r= -0.80, p<0.001) and posterior (r= -0.71, p<0.001) segments whereas only a weak relationship was found between PCWP and E/Em (p<0.05). The sensitivity and specificity of using a negative T IVRT-IVRTm for identifying patients with PCWP >12 mm Hg were 89 and 90%, respectively. CONCLUSION: We found a highly significant correlation between T IVRT-IVRTm and PCWP, which was not seen for E/Em. We propose T IVRT-IVRTm as a stronger predictor of LVFP. T IVRT-IVRTm also seems to correlate to LVFP for many different clinical aetiologies of elevated LVFP.