Change in filling pattern with preload reduction reflects left ventricular relaxation

Background: The early diastolic mitral valve pressure gradient and the rate of left ventricular filling are determined by the rate of left ventricular relaxation and left atrial pressure at the time of mitral valve opening. Accordingly, we hypothesized that the left ventricular filling pattern with preload reduction can be used to estimate left ventricular relaxation in patients with preserved systolic function. Methods: We evaluated the relationship between the logistic time constant of left ventricular relaxation and left ventricular filling pattern calculated from the time derivative of left ventricular volume using a microtipmanometer and a conductance catheter in 26 consecutive patients with preserved left ventricular ejection fraction (>45%). Left ventricular filling patterns were determined from the maximal rates of early diastolic left ventricular filling (E velocity) and atrial filling (A velocity) before and after preload reduction by inferior venal caval occlusion. Results and conclusions: There was no significant relationship between the logistic time constant of left ventricular relaxation and the E/A velocity ratio at baseline. However, the time constant was correlated with the E/A velocity ratio after venal caval occlusion (r=−0.47, p=0.02). Furthermore, the time constant was correlated with %E/A velocity change, which was defined as the rate of change of E/A before and after caval occlusion divided by E/A after caval occlusion, more significantly (r=−0.67, p<0.01) than with the E/A velocity ratio after caval occlusion. Thus, the left ventricular filling pattern with preload reduction can be used to estimate left ventricular relaxation in patients with preserved left ventricular ejection fraction.